N,N'-divinylalkylurea crosslinked polymers, a process for their preparation, and their use
AssigneeHoechst Aktiengesellschaft
InventorsOtto Mauz, Siegfried Noetzel, Bernhard Neumann
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Abstract
The invention relates to crosslinked polymers based on polyvinyl acylate or polyvinyl alcohol and having crosslinking agent units which are derived from crosslinking agents of the general formulae ##STR1## and/or ##STR2## These products, inter alia, are particularly hydrolysis-resistant and can have high crosslinking densities. The invention also relates to a process for preparing these polymers and to their use in chromatography and as carriers for biologically active substances.
Claims17
An absorbent in chromatography or a carrier material for biologically active substances comprising a crosslinked polymer which consists essentially of (a) vinyl acylate units and (b) units of at least one crosslinking agent of the formula ##STR6## in the presence or absence of (c) units derived from an additional monomer which is copolymerizable with (a) wherein R.sub.1 and R.sub.2 in the formula (I) are identical or different and each denotes vinyl-, 1-acyloxyvinyl, allyl-, or 2-acyloxyally, A represents a divalent hydrocarbon radical of 2 to 8 carbon atoms, the units of the crosslinking agent accounting for 0.1 to 60% by weight of the polymer and wherein the acylate groups of the vinyl acylate units are at least partially hydrolyzed.
A process for preparing a crosslinked polymer consisting essentially of vinyl acylate units and units of at least one crosslinking agent of the formula ##STR7## wherein R.sub.1 and R.sub.2 in the formula (I) are identical or different and each denotes vinyl, 1-acyloxyvinyl, allyl or 2-acyloxyallyl, A represents a divalent hydrocarbon radical of 2 to 8 carbon atoms, the amount of these crosslinking agent units accounting for 0.1 to 60% by weight of the polymer comprising the steps of:
- bead polymerizing (i) vinyl acylate with (ii) a crosslinking agent of formula (I) in the presence or absence of (iii) an additional monomer which is present in an amount not exceeding 10% by weight of the total polymer, and which is copolymerizable with the vinyl acylate, said bead polymerizing step occurring at a temperature of 20.degree. C. to 150.degree. C. and under a pressure of 1 to 10 bar in the presence of (iv) a dispersion medium;
- (v) at least one inert diluent present in a volume of 0.02 to 5 times the volume of monomers used, (vi) a dispersion stabilizer and in the absence or presence of (vii) a further additive and (viii) a free-radical initiator with the exclusion of oxygen, and
- hydrolyzing at least partially the acylate groups of the resulting polymer.
Dependencies are inferred from the claim text.